The invention relates to sliding vane rotary power devices, and more particularly to internal combustion engines, pumps, compressors, fluid-driven motors, expander devices, fluid-driven pumps and compressors, where various ones of those devices differ from others by a simple modification of a central stator member.
This invention relates to a rotary power device of the radial sliding vane type. These types of devices are characterized in having a rotor assembly comprising a number of vanes equally spaced about the rotor so as to divide the rotor chamber into discrete cavities. As the rotor turns, the vanes follow the wall contour of the rotor chamber and thereby provide cavities that rotate with the rotor. The rotor chamber has an axis that can be concentric or eccentric with respect to the axis of the rotating member. This invention belongs to the former type in which the axis of the substantially oval-shaped chamber coincides with the axis of rotation and the chamber comprises two diametrically opposed quadrants of expanding cavities that are alternated by another two quadrants of contracting cavities. In a typical four-cycle engine the processes of intake, compression, power and exhaust are distributed equally among the four quadrants. Additionally, the sliding vane device of the present invention can be configured to operate as a double-action pump or compressor, an expander device, a fluid-driven pump or compressor and a two-cycle internal combustion primarily through the replacement of a central stationary member and a rearrangement of exhaust ports.
Sliding vane rotary devices generally comprise straight vanes slidably received within respective slots radially formed in a rotor. As the rotor spins, vanes are driven outward by centrifugal forces to an extent constrained by the wall contour, and execute radially reciprocating motion as the rotor spins. In an effort to reduce vane tip loading and increase outward radial movement response, a variety of vane actuation methods have been developed. One class of devices employs a biasing spring disposed at the base of the vane. Another class uses a pair of controlling sidewall cam grooves engaged by sub-shafts fixed to lower side portions of a vane. Still another class uses a transfer passage connecting a pressurized fluid to the base of the vanes. Although the functionality of such means of vane actuation have been proven, they are characterized in some respects with excessive friction, fluid slip, leakage, and complexity. Examples of rotary devices of the above type can be found in various United States patents such as U.S. Pat. No. 6,030,195 to Pingston; U.S. Pat. No. 4,355,965 to Lowther; U.S. Pat. No. 5,415,141 to McCann; U.S. Pat. No. 4,353,337 to Rosaen; and U.S. Pat. No. 4,018,191 to Lloyd.
The present invention provides a rotary power device that can be configured, among other things, to serve as a two or a four cycle internal combustion engine, a motor-driven pump or compressor, a fluid driven pump or a compressor by replacing a stationary central member. Preferred embodiments of the invention comprise a toroidal block rotor assembly having a centrally bored portion. This rotor assembly may be fixedly secured to an end shaft and rotatably carried at one end of an external stator housing. The central bored portion of the rotor communicates with a plurality of radially disposed open-ended compartments. The radial compartments are disposed alternatively along the circumference of the rotor so as to provide an equal number of radial slots. An external stator portion of the device preferably comprises a partially toroidal chamber having an axis coincident with the rotational axis of the device. In a preferred embodiment of the external stator, the toroidal chamber is split along a plane perpendicular to the axis at a point corresponding to the center of the rotor, thus forming two mating halves. Each half comprises a cam groove along an edge of the respective mating face. When the external stator is assembled, the two grooves mate together to form a single cam track having a contour similar in shape to the inner peripheral toroidal wall contour. Moreover, as is shown in FIGS. 4 and 5, the preferred cam track has a re-entrant, or undercut, shape when viewed in a radial section perpendicular to the track so that the track can capture a cam follower. Sliding and rolling cam follower elements, such as ball elements, can engage this track and be captured therein. Each preferred vane comprises an outer tip ring portion for enclosing a respective ball element that is entrapped within the cam track so as to serve as a cam follower. The tip ring portion is fixedly connected to the main body of the preferred vane by an elongated portion having a diameter selected to fit through a narrow neck portion of the reentrant cam track. Because the preferred cam follower and track arrangement provides for capturing the follower within the track, this arrangement allows each associated vane to be both pulled away from the axis of rotation and pushed towards the axis of rotation, thus causing reciprocating sliding movement of the vanes in their respective slots as the rotor rotates.
Furthermore, preferred devices comprise an internal stator fixedly secured to the external stator and rotatably enclosed, with clearance, within the central bored portion of the rotor. The internal stator comprises channels connected to ports communicating with inner opening of the rotor compartments. As the rotor spins, a cavity formed between two adjacent vanes defining a radial compartment intermittently communicates with the ports in the internal stator so as to perform intake, compression, power and exhaust functions. Other embodiments may comprise ports and passages in both the internal and the external stator portions. In addition to embodiments serving as two-cycle or four-cycle internal combustion engines, the rotary device of the invention can function as motor-driven or fluid-driven pump or compressor by replacing the internal stator with one having an appropriate port and channel configuration.
One object of some embodiments of the invention is to provide a radial sliding vane power device having a simple, efficient and less costly means of vane actuation.
A further object of some embodiments of the invention is to provide an improved radial vane rotary power device that is light in weight, small in size and that has the minimum number of parts.
Another object of some embodiments of the invention is to provide a rotary power device that can be easily converted to other type of rotary power device such as four-cycle or two-cycle internal combustion engine, pump, compressor, expander, fluid-driven motor and fluid-driven pump devices by a simple modification or replacement of a central stationary member.
Another object of some embodiments of the invention is to provide a rotary power device that closely approximates continuous intake, compression, combustion and discharge processes.
Yet another object of some embodiments of the invention is to provide a dynamically balanced radial vane rotary power device characterized by reduced noise and vibration.
An additional object of some embodiments of the invention is to provide a rotary power device with reduced friction, fluid slip and leakage.
These and other objects and advantages of the present invention will be apparent from the following detailed description and the appended claims.
Although it is believed that the foregoing recital of features and advantages may be of use to one who is skilled in the art and wishes to learn how to practice the invention, it will be recognized that the foregoing is not intended to list all of the features and advantages. Moreover, it may be noted that various embodiments of the invention may provide various combinations of the hereinbefore cited features and advantages of the invention, and that less than all of the recited features and advantages of the invention may be provided by some embodiments.